Tokyo Electric Power Co. has released video footage taken inside the damaged containment vessel of the No. 1 reactor at its Fukushima No.1 nuclear power plant, the first such footage the utility has released since the crisis that erupted at the plant in March of 2011.

The video, taken Wednesday using an endoscope, shows an area around a pipe that sits about 8.5 meters from the bottom of the containment vessel. The scattered debris that is visible is believed to be damaged parts of the vessel’s internal structure.

To insert the endoscope, a hole was drilled through a 30-centimeter-diameter pipe that had become blocked by a steel plate and other debris.

The investigation revealed that a 7.5-centimeter-thick lead plate had disappeared from inside the vessel, presumably lost after the hydrogen explosion March 12.

Temperatures inside the containment vessel rose to more than 700 C three days after the explosion, meaning the plate probably melted. The melting point of lead is 327 C.

TEPCO plans to conduct further research in October by measuring such things as the water level, temperature and radiation levels inside the vessel using a thermometer, camera and an instrument to collect water.